In 1985, 24 bottom samples were collected in each of two slightly brackish,semi-permanent prairie wetlands (P1 and P4) with different hydroperiods. The main objective was to determine if hydroperiod affected seed pool characteristics. Additionally, 48 samples were collected in 1986 from wetland P1 to determine if seed bank composition changed annually without a change in mature vegetation. Seed bank composition was determined by placing soil samples in a greenhouse, then counting and identifying emerged seedlings. As a check against the seedling emergence method, seeds were separated and identified microscopically in one-third of the 1985 samples. Results indicated that the emergence method was an accurate technique for assessing seed pool composition. The wetlands did not differ in floristic composition (i.e., presence/absence) but did in species densities. The mean relative density of mudflat annuals in all seed pool samples was significantly greater in wetland P4 (82%) than in P1 (52%). A shorter hydroperiod in this wetland produces more frequent drawdowns and a greater input of mudflat annual seeds. Conversely, seeds of emergent species were more abundant in the seed bank of wetland Pl (48%) compared to P4 (17%). The former wetland has a longer hydroperiod and less frequent drawdowns, and thus, the primary seed input is from emergent plants. / Master of Science

Thesis (M. Sc.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 71-73).

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Bibliography: leaves 133-134. / by Stephen R. Cassella. / M.C.P.

Coastal ecosystems, such as the salt marsh of the Georgia coast, have long been valued for decision-making purposes based on market-values of goods and services including: fishery landings, hedonic pricing of waterfront homes, and tourism dollars. These values do not show the full picture of services provided by these ecosystems. Using focus group discussions and key informant interviews I investigate socio-cultural values and benefits provided by salt marsh ecosystems in central coastal Georgia. Participants noted that through their experiences in marshes they developed a desire to be stewards. This desire, coupled with the industrial pollution, residential development, and sea-level rise threats in the area result in a need for cooperative conservation and thus better enforcement of existing regulations. This relational value persisted across geographic locations and sample populations. My results show the importance of utilizing diverse members of community to elicit qualitative value statements. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

Human reliance on the goods and services provided by ecosystems and the global decline in the health of many of these ecosystems, necessitates ecosystem valuation for the purposes of decision-making and conservation policy. The literature suggests that conventionally employed economic valuation methods have been unsuccessful in capturing the full scope of the benefits ecosystems provide, particularly those benefits that are considered cultural. This research explores public perceptions of salt marsh value through the use of focus groups in marsh-adjacent communities in Massachusetts, Virginia, and Georgia. Results suggest that in case study communities, outdoor experiences in salt marshes inspire serenity in Massachusetts, shape shore and “marsh” identities in Virginia, and promote stewardship cultivation in Georgia. Perceived threats to these benefits, such as the threat of residential development, industrial pollution, and increasing flood risk, together constitute the context for various community responses related to marsh protection. Results contribute to existing economic valuations. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

I studied nutrient reserves, digestive organs, molt intensity, diets , and seasonal changes in food resources available to postbreeding adult male Northern Pintails (Anas acuta) and Cinnamon Teal (Anas cyanoptera) in marshes near Great Salt Lake, Utah. Total lipid and protein reserves of Northern Pintails were lower during the flightless period than before or after. For Cinnamon Teal, total protein was lowest during the flightless period, and total lipid showed a similar trend. Total mineral did not differ among plumage classes in either species. Use of nutrient reserves in these species may be an endogenous rhythm in response to increased predation risk or unpredictable food resources while flightless. Digestive organ metrics of Northern Pintails generally were lower while flightless than before or after, apparently due to decreased dietary consumption. Cinnamon Teal digestive organ metrics changed little from preflightless to flightless stages, but generally increased while postflightless. Changes in Cinnamon Teal digestive organs may be related to increased dietary intake or increased dietary fiber consumption. Total molt intensity in these species was generally high before and during wing molt, and decreased during the postflightless period. Mathematically weighting total molt scores produced results similar to those obtained without weighting, but selection of body/feather regions is critical to obtaining unbiased estimates. Changes in relative availability of plant and animal foods during July and August were marked . Animal foods made up 96% of total foods measured in the study area during early July, but plant foods comprised 95% of available foods by late August. Changes in abundances of food resources are probably an important determinant of diet selection in postbreeding adult ducks and ducklings in marshes near Great Salt Lake. Diets of postbreeding adult male Northern Pintails and Cinnamon Teal did not differ between species, but did among flight classes. Changes in use of food items and in use of animal and plant foods were consistent with changes in relative abundances of food resources. Postbreeding adult males of these species apparently foraged opportunistically.

No description available.

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: John C. Kraft, Dept. of Geology. Includes bibliographical references.

Thesis (doctoral)--Ecole des hautes études en sciences sociales, 1981. / Includes bibliographical references (p. 275-281).

Soil organic matter (SOM) provides many ecosystem services that are necessary for continued ecosystem function. The accumulation of SOM in an ecosystem is a function of its persistence time which can range from days to thousands of years. Ecosystem properties including dominant vegetation type, soil texture, and soil moisture in various habitats can regulate the persistence time of SOM. Wetlands, because of their associated ecosystem properties, promote SOM accumulation, but little has been done to determine the ecosystem properties that regulate its persistence over time. In west-central Florida, urbanization and increased water demands have suppressed water tables in isolated wetland ecosystems via hydrological connectivity between ground and surficial waters. In this study, variability in wetland ecosystem properties, in particular dominant vegetation type and hydrological parameters, were tested as mechanisms driving SOM accumulation and stability. Cypress wetlands had significantly more organic matter, carbon (C), and nitrogen (N) than herbaceous marshes. In addition, increased wetland inundation promoted stable SOM accumulation in forested wetlands. By increasing the percent time a forested wetland spent aerobic, decreases occurred in both labile and stable C and N pools. As large storage units of SOM, the decreases in both labile and stable C and N pools in wetland soils have large implications for global C and N cycling. Increased manipulation of wetland water levels, especially in short time scales, can mineralize both short-term and long-term storage units of C and N. Globally, the increase mineralization of large SOC and SON stocks would exacerbate the release of air and water quality pollutants. The sensitivity of both labile and stable SOM pools draws concern when anticipating continued water demands and land use changes of the Tampa Bay region.